Vouchers take 30 days or up to 90 depending on the offer and are not normally sent in a letter. They can't be used until you are well past a cooling off period.
That is just confirming address details.
Usually vouchers arrive by email and then need to be redeemed online, @Parky5.
Your post is in a queue for further assistance from staff.
Gliwmaeden2, a fellow customer.
